U.S. Border Patrol agents began watching the boat carrying 19 men and six women about 5 a.m. after suspecting it was involved in a smuggling operation, said Virginia Kice, a spokeswoman for U.S. Immigration and Customs Enforcement.

Authorities arrested those aboard after they landed near Abalone Cove and came ashore shortly about 8 a.m.

In addition to ICE, the U.S. Coast Guard and several state and local law enforcement agencies are assisting in the investigation.

Some passengers cried as they were photographed and interviewed by Department of Homeland Security investigators. Most were dressed casually in sweatshirts and jeans.

"The 25 individuals are being interviewed by (Homeland Security) investigators to develop further evidence related to the smuggling attempt and identify any suspects who were complicit in the scheme," Kice said.

"Those subjects who are not held for possible criminal prosecution will be remanded to the custody of the U.S. Border Patrol to be processed and repatriated."

Kice said most of the human smuggling cases the agency encounters originate in Mexico, but officials had not determined the nationality of this group by Monday afternoon.

Two minivans were recovered near the boat landing site, she said. Investigators believe they were intended to be used to "transport the smuggled aliens away from the landing site," Kice said.

The undocumented immigrants likely will be deported after they are interviewed, but some may remain as witnesses in case criminal charges are filed against the smugglers, she said.

"The broader goal is not only to identify any individuals in this group who may have been complicit in the broader smuggling scheme, but also to identify higher operatives so we can dismantle the broader criminal organization involved," Kice said.

Maritime smuggling activity has increased off the Southern California coast in recent years, Kice said, with more than 200 intercepted human- and drug-smuggling operations occurring this year alone.

In one of those encounters, U.S. Coast Guard Senior Chief Boatswains Mate Terrell Horne III was killed Dec. 2 as he and others approached a panga suspected of being involved in drug smuggling off the coast of Santa Cruz Island.

Horne, a 34-year-old Redondo Beach resident, was approaching the panga with three other investigators in an inflatable boat when the suspect's vessel rammed them. Horne, a married father of two with a third child on the way, suffered a fatal head wound when he and another man were thrown into the ocean.

The incident was the first time in recent memory that an officer had died during an interdiction with a panga, a Coast Guard spokesman said last week.

Federal prosecutors subsequently charged two Mexican nationals - Jose Meija-Leyva, who told investigators he was the captain of the boat, and Manuel Beltran-Higuera - with killing an officer of the United States while engaged in his official duties.